case 2 tuberculosis Flashcards
what organism causes tuberculosis infection
mycobacterium tuberculosis
what does mycobacterium tuberculosis contain in its cell wall
mycolic acid
cell wall is hydrophobic
mycolic acid affects permeability
what are the four antibiotics used to treat TB
-rifampicin
-isoniazdi
-pyrzanimide
-ethambutol
how long is the antibiotic course for tb
- 6 months
for the first two months what tb antibiotics are taken
all four
for the rest of the four months of the course what antibiotics for tb are taken
rifampicin and isoniazid
what is tb resistant to
common antibiotics
killing by acid/alkaline agents
is tb aerobic
highly aerobic and adaptable
o2 tension and nutrient availability vary during disease
how is tb spread
through droplets in the air
how does tuberculosis cause infection
bacteria survive inside macrophages
granuloma formation
hosts attempt to limit the spread of bacteria
granuloma- collection of activated macrophages called epithelioid cells surrounding an area of necrosis
bacteria can survive and replicate inside macrophages
tb can affect cns, bones,lungs, pericardium and lymph nodes
what areas of body can tb affect
cns, bones, lungs, pericardium, lymph nodes
how does tb evade phagocytosis
phago lysosome fusion
resists phagosome acidifcation
resists degradation by lysosome
escapes from endosome
metabolic adaptability
what disease symptoms can tb cause
fever
weightloss
chronic coughing
haemoptysis
local tissue destruction
how many months is tb treated for
6
how is tb screened
mantoux test lack of specificity as does not indicate whether infection is latent or active just indicates that body has been exposed to tb
